Many tools and appliances are used while being supported by one hand of the user. Such tools as brushes, paint rollers, window squeegees, scrapers, spray wands, certain brooms, shovels, rakes and the like, use elongated poles as part of their structure. It is common knowledge that when so used, such devices place a great deal of strain on the hand and wrist of the user. The long lever action of such tools amplifies the force required to be exerted by the hand and wrist of the user in order to exert a force at the working end. Torsional, lateral and axial forces must be transmitted from the hand and wrist to the device, causing awkwardness, fatigue, and sometimes injury.
The prior art is replete with efforts to distribute the forces experienced in the use of hand tools and appliances from the hand and wrist to the forearm, in order to relieve the pressure and strain on the wrist itself. A considerable number of prior art devices couple a handle with a brace of some sort which surrounds the forearm. Hence cuffs, bands, cradles, etc. are linked by a rigid structure to the handle. The handle is either integrally formed with the device or is equipped with a coupling device for more universal use. The efficacy of the prior art devices is generally defeated by the varying size and structure of the user, the diversity of stresses distributed to and from the tool, or discomfort experienced by the user. In addition, there is generally difficulty in installing the support on the forearm, which often requires the use of the other hand.
Typical structures of the prior art are shown in U.S. Pat. Nos. 5,445,479; 5,564,451; and 5,890,259. Each of these patents describe devices which employ an upright handle attached by a rigid bar or bars extending up the arm to a cuff. In each instance the cuff circumscribes the arm in a single transverse plane to engage the upper arm and distribute forces. The devices of '451 and '479 patents provide adjustable straps to accommodate different sizes, while the '259 patent appears to be one size fits all. U.S. Pat. No. 5,156,429 is an “S” shaped bar which, in the preferred embodiment, extends from a handle up the arm to provide engagement on several sides of the arm. By not fully enclosing the arm, it can accommodate different sizes and also makes it easier to mount on the arm.
It is a purpose of this invention to provide a mechanism for distributing forces and stress exerted by and on the hand and wrist to the forearm. It is another purpose of this invention to provide a brace which is designed for comfortable use by the great majority of potential users without regard to diverse arm sizes. It is also a purpose of this invention to provide a multipurpose handle which can be used in a wide variety of applications, in particular, those involving tools and appliances which have an elongated pole or shaft as part of their construction. Such devices are difficult to use effectively with one hand. It is also a purpose of this device to facilitate the installation and removal of the brace on the arm, so that it can be easily engaged without the use of the other hand, and without threading the hand and arm through a circular opening.
It is also a purpose of this invention to provide a multipurpose handle which can be used with hand tools such as power drills, nail guns, paint sprayers, etc., which may include a “pistol grip” as part of existing design and common use.